Field of the Invention
The present invention relates to a control method of a network system.
Description of the Related Art
With the sophistication of web applications, various function enhancements are made in HyperText Markup Language 5 (HTML5). Among the enhanced functions are web storage and IndexedDB functions for storing data in a storage area intended for a web browser.
Web storage can automatically store data into a storage area of an information terminal such as a personal computer (PC) or a smartphone from a web server side providing a website at the timing when the website is browsed. Such an enhanced function makes services that the website provides available by using locally cached data even if the PC or mobile terminal browsing the website is offline.
There has recently been a technique for sharing information about open tabs between web browsers of different information terminals. According to such a technique, for example, a website that has been browsed in a tab of a web browser of a tablet terminal can be instructed to be displayed and browsed on a web browser of a portable terminal, and vice versa.
Japanese Patent Application Laid-Open No. 2013-120603 discusses a conventional technique for sharing data between web browsers. According to the technique discussed in Japanese Patent Application Laid-Open No. 2013-120603, a server receives data determined to be sharable between web browsers, from a web browser, and stores the data. The server then transfers the stored data to a web browser of another information terminal to achieve the data sharing between the web browsers of the different information terminals.
Web storage described above includes two types of data storage modes LocalStorage and SessionStorage. LocalStorage is specified to share data in a storage area between different tabs of a web browser on an information terminal. SessionStorage is specified not to share data in a storage data between different tabs of a web browser on an information terminal. LocalStorage and SessionStorage have such a difference in specifications.
As described above, SessionStorage is specified not to share data between different tabs. According to such a specification, SessionStorage is not able to be handed over or shared between different information processing apparatuses. If SessionStorage is shared and used by different information processing apparatuses, an operation intended by the website side may be unable to be implemented because the shared use of data of SessionStorage between different information processing apparatuses violates the original specification.
The technique for sharing data between web browsers discussed in Japanese Patent Application Laid-Open No. 2013-120603 does not take account of data of such a specification for not sharing data between different tabs of a single web browser like SessionStorage (session storage). If data of a specification for not sharing data between different tabs of a single web browser like SessionStorage is shared and used between web browsers of different information processing apparatuses by using the technique discussed in Japanese Patent Application Laid-Open No. 2013-120603, an operation intended by the website side may be unable to be implemented as described above because of the violation of the original specification.